Extended Assignment of Themes Doesn't work

I'm using the Taxonomy Theme on Drupal 6. I am able to change the themes of different vocabulary and terms but the "extended assignment of themes" which would allow me to assign a new theme to a different path (e.g. node/18) simply does not work. I type in the path I want changed, hit "save configuration" and it just reloads the same page, erasing whatever I had written in. I've looked through the other threads and haven't seen a similar inquiry pop up yet. I'm also running the "taxonomy context" and "taxonomy menu" modules, I don't know if those have been known to interfere.